One vertex per element, one color per generator, with an edge from x to x·s.
(9,10,14,17)(11,18,13,15)(12,16,21,24)(19,23,20,22)(25,26,30,31)(27,34,29,32)(28,36,37,33)(35,39,38,40)(1,2)(3,5)(4,6)(7,8)(9,11,14,13)(10,15,17,18)(12,20,21,19)(16,23,24,22)(26,31)(28,37)(32,34)(35,38)(2,3)(6,7)(12,21)(16,24)(19,20)(22,23)(25,27,30,29)(26,32,31,34)(28,38,37,35)(33,40,36,39)(4,8)(6,7)(9,10)(11,15)(12,16)(13,18)(14,17)(19,22)(20,23)(21,24)(25,26)(27,32)(28,33)(29,34)(30,31)(35,39)(36,37)(38,40) involution — undirected(1,3,5,2)(4,7,8,6)(9,12,14,21)(10,16,17,24)(11,19,13,20)(15,22,18,23)(25,28,30,37)(26,33,31,36)(27,35,29,38)(32,39,34,40)(1,4)(2,6)(3,7)(5,8)(9,13,14,11)(10,15,17,18)(12,20,21,19)(16,22,24,23)(25,29,30,27)(26,32,31,34)(28,38,37,35)(33,39,36,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.